| 摘要 |
PROBLEM TO BE SOLVED: To achieve miniaturization and to increase service life by providing opening parts on both sides of a spacer, forming one opening part having an opening area larger than that of the other opening part, and mounting the wider opening part on a reflector opening part. SOLUTION: A spacer 4 is made of ceramic, one opening part 4a has the opening area wider than that of another opening part 4b, and the wider opening part 4a is fixed to an opening part of a reflector 2 by adhesives. The angle of the inner peripheral surface of the spacer 4 and the reflection factor of the front surface way be determined properly to a range such that a lamp is not largely affected by light reflected by the inner peripheral surface of the spacer 4. Accordingly, this spacer 4 does not disturb a necessary condensing optical path so as to prevent excess light to a device from being irradiated. As a result, excess reflected light from the device is decreased, and therefore the bulb temperature rise caused by burn-off of a molybdenum pin of a lamp seal part on the opening part side of the reflector 2, oxidation of a spot part of molybdenum and molybdenum foil, or the reflected light can be restrained. |
